Process of making mixed water gas and oil gas



June 11, 1929. w b, w cgx 1,716,676

PROCESS OF MAKING MIXED WATER GAS AND OIL GAS Filed Dec. 31, 1924 Imam???" Patented June 11, 1929.

UNITED STATES PATENT OFFICE.

WILLIAM D. WILCOX, OF IDAHO FALLS, IDAHO.

PROCESS OF MAKING MIXED WATER GAS AND OIL GAS.

Application filed December 31, 1924. Serial No. 759,167.

o tightly closed ovens or retorts so as to drive oil the volatile portion as coal gas, or burned as generator fuel in place of coke or anthracite coal for the production of water gas.

Its use in water gas generators of the type originally designed. for operation with coke or anthracite coal is handicapped and the efliciency of gas production reduced by the fact that in blasting with air, the hot combustion products passing up through the freshly charged coal carry oil a large percentage of ments in the coal are given off at temperaturesthe rich hydrocarbon volatiles of .the coal as gas and tar,'to be destructively consumed in the carburetor which forms part of the standard water gas set. Since these volatile elesubstantially lower than the temperature required to disassociate steam to form water gas, it is not possible to bring the temperature of the coal to that required for the production of water gas until the absorptionot' heat by the evolved gases and their evolution have practically ceased. The upper portion of a. body of bituminous coal charged into a water gas generator is therefore inactive so far as relates to the breaking up of the steam during the run period and the rate of water gas made per square foot of grate area and height of fuel is substantially reduced.

The purpose of my invention is to conserve so far as possible the volatiles of the coal as gas, tar,'and ammonia, and to secure the best thermal eflicienc by reducing the fuel loss resulting fromt e escape of sensible heat in both the conserved and blast gases.

The process will be better understood by reference to the accompanying drawing, which shows a vertical cross section of the apparatus. F is a water gas generator in which A is the carbonizing zone, B the combustion and gas vgeneratin zone; 1 is the charging lid; 2 is a gas out et pipe leading from the generator controlled by a valve as is usual; 3 is a circular passage enclosed within the brick lining and outer steel jacket of the generator, into which air is admitted under pressure through air supply pipe 4; nostrils 5 spaced at regular intervals around the inner circumfereneeref thegeneggpg admit air'from 3 to the interior; 6 1s a grate; 7 is awzimkermg nletg glosed, and steam inlet 18 opened. The door; 8 1s a steam nlet; 9 1s a door for the resteam entermghereand. passing downward moval of ash; 10 is a passage leading from the lower part of the generator to a preheater, regenerator, or secondary combustion chamber C 11 is an inlet for the admission of air to complete the combustion of the blast gases in C; 12 is a ring which may be replaced by a flange so as to close 10; 13 is a flange closing the stack 23, which may be removed and replaced by a ring so as to permit the products of combustion to pass directly through the stack to the atmosphere; 22 is a brick lining within the steel outer jackets of F and G; 15 is a door for cleaning out dust and ashes from the base of C; 14 is a brick arch which supports checker brick; 16 indicates the checker brick placed above this arch; 17 is an opening in the side of C through which an oil spray may be introduced; 18 is a steam inlet; D is a vertical steam boiler having fire tubes 19; 20 is a passage from the upper part of the boiler to the stack; 21 is a stack valve; 24 is a ring which may be replaced by a flange for closing passage 20.

In operation, B is filled up to the level of nostrils 5 with coke, eithercharged initially or resulting from the prior distillation of bituminous coal in A. A is filled with bituminous coal in various stages of carbzonization. During the air blast period, the valve on gas outlet 2 is substantially closed, but will preferably be left partly open so that the volatiles coming ofli' from the coal in A will be forced out through 2 by the pressure of the air entering from nostrils, 5 without any substantial volume of this air passing upward. The stack valve 21 is open.

Following'the path of least resistance, the air passes downward through the fuel in B, bringing it to a state of high incandescence. The carbon monoxide content of the air blast gases passing into C through 10 are burned by the air entering at 11, heating the walls of C and checker brick 16, thence through boiler D to the stack.

Gas may be made with no greater degree of carbureting than is supplied by the admixture with the water gas generated in B of the coal gas given off by the coal in A. When this procedure is followed, the air supply through 3 and 11 will be shut off, steam will be admitted through 8 to drive the blast gases out of C. The stack valve will then be closed, the valve on gas outlet 2 opened fully steam under boiler pressure becomes highly superheated by contact with the checker brick 16 and enters the fuel above grate 6 in F at a temperature very close to that at which steam is dissociated when brought in contact with hot carbon.

Less demand is made upon the heat stored in the fuel in B and a larger volume of water gas produced per pound of fuel than would be possible using steam at a temperature at or below that indicated by the boiler pressure. The resultant Water gas and undecomposed steam enter the upper level of coal in A at a high temperature. They impart to the coal therein by direct contact a'large portion of their sensible heat so that when the coal has descended at a rate determined by the consumption of fuel in B to the level of nozzles 5, it has become substantially coked and has been brought to a temperature very nearly as high as that of the water gas by which it is heated.

When it is desired to send out a gas of higher thermal value per cubic foot, operation will be somewhat difi'erent. The air blasting will be carried on as described. After blasting and purging, valve on 2 will be opened and stack valve closed; and steam will be admitted through 8 for a short period of two or three minutes or thereabouts after which for a further period (the length" of which may be determined by operating experience) oil will be sprayed from a spraying nozzle introduced through 17, while at the same time steam is admitted through-18. The mixed oil vapor and steam are passed through A and B to outlet 2 and are converted to gas. I

The reason for admitting steam through 8 rather than 18 during the first portion of the run is twofold; first, to avoid lowering the temperature of the checker brick in C below that necessary to vaporize the oil; second, to reduce the temperature of the fuel in B below that which will overheat and break up the oil vapors with a deposit of lamp black and production of naphthalene.

In the event of repairs being needed to Cor D, they can be shut off and F operated independently, using steam from another boiler and passing the blast gases up stack 28.

What I claim and wish to secure by Letters Patent is:

1. The process of making mixed water gas and oil gas in a gas generator having a fuel bed which comprises; blasting the fuel with air admitted at an upper level of the generator, causing the blast gases to pass downwardly and. into a regenerator, heating the regenerator by burning the blast gases therein, passing steam into the base of the generator and upwardly through the fuel bed of the generator for an interval to generate water gas and thereby reduce the temperature of the blasted fuel, withdrawing the resultant water gas from the upper part of the generator, then admitting steam and oil to the upper part of the regenerator, vaporizing the oil and steam mixture by passing it downwardly through the regenerator and then passing the heated oil'and steam mixture through the heated fuel in the generator, and thereby forming mixed water gas and oil gas; and withdrawing the mixed water gas and oil gas from the upper part of the generator.

2. The process of making mixed water gas and oil gas which comprises; admitting air under pressure to an intermediate level of a bed of bituminous coal in a gas generator, causing the air blast gases to pass downwardly, thence through an outlet in the lower part of the generator into a reeene'rator and heat ing the regenerator by burning the combustible blast gases therein, then admitting steam to the lower part of the fuel bed of the generator for an interval and causing it to pass upwardly through the fuel therein, withdrawing the resultant water gas from the upper part of the generator, then admitting steam and oil to the upper part of the regenerator, heating the steam and vaporizing the oil by passing them downwardly through the regenerator, thence into the generator and upwardly through the fuel therein, and withdrawing the mixed water gas and oil gas from the upper part of the generator.

YVILLIAM D. WILCOX. 

